Backpack



FIG. 1 shows a front perspective view of a backpack;

FIG. 2 shows a front elevation view of the backpack of FIG. 1;

FIG. 3 shows a rear elevation view of the backpack of FIG. 1;

FIG. 4 shows a left elevation view of the backpack of FIG. 1;

FIG. 5 shows a right elevation view of the backpack of FIG. 1;

FIG. 6 shows a top view of the backpack of FIG. 1; and,

FIG. 7 shows a bottom view of the backpack of FIG. 1.

The dashed lines in FIGS. 1-7 show the environment and boundaries of the backpack and form no part of the claimed invention. 

CLAIM The ornamental design for a backpack, as shown and described. 